We went to Disney World when dd#2 was 3 1/2 months. We asked our pedi about sunblock because we knew sometimes we just wouldn't be able to keep her out of the sun but she was less than the 6 month recommendation. Our pedi said the 6 month recommendation is mostly because they prefer you to keep babies out of the sun when they're little. Sunblock hasn't been tested for young babies but there are no indications it will harm them. Basically he told us - keep her out of the sun if you can but when it isn't possible put sunblock on her. But don't do hands or around the mouth. We only needed it for her a couple of times during a parade or something like that. We mostly kept a hat on her head and a light layer on her arms until it got too warm for even that much.